theorem Th23:
  p is universal & bound_in p <> x implies p.x = All(bound_in p,(
  the_scope_of p).x)
proof
  assume p is universal;
  then (p.x) = IFEQ(bound_in p,x,p,All(bound_in p,(the_scope_of p).x)) by Lm3;
  hence thesis by FUNCOP_1:def 8;
end;
